n marked; and the adjacent joint
may be distended with fluid.

As distinguishing this injury from a dislocation, it may be noted that
in epiphysial separation there is no snap felt when the deformity is
reduced, the tendency to re-displacement is greater, and the amount of
relief given by reduction less than in dislocation. The use of the
Roentgen rays at once establishes the diagnosis.

_Prognosis and Results._--In the majority of cases union takes place
satisfactorily by the formation of callus in the spongy tissue of the
diaphysis and on the deep surface of the periosteum. In spite of the
favourable nature of the prognosis in general, however, the friends of
the patient should be warned that a completely satisfactory result
cannot always be relied upon.

Deformity, with stiffness and locking at the adjacent joint,
especially at the elbow, may result from imperfect reduction, or from
exuberant callus. Arrest of growth of the bone in length is a rare
sequel, and when it occurs, it is due, not to premature union of the
epiphysis with the shaft, but to diminished action at the ossifying
junction.

When the growth of one of the bones of the leg or forearm is arrested
after separation of its epiphysis while the other bone continues to
grow, the foot or hand is deviated towards the side of the shorter
one.

Partial separations may be overlooked at the time of the accident and
cause trouble later from bending of the bone, as in one variety of
coxa vara. The epiphysis at the lower end of the femur may be
displaced into the ham and press on the popliteal vessels.

_Treatment._--The general principles which govern the treatment of
fractures apply equally to epiphysial separations, the essential being
the accurate replacement of the epiphysis.

In _compound separations of epiphysis_, the end of the diaphysis may
be pushed through the skin. The entrance of sepsis may prove an
obstacle to any operative measure that would otherwise be indicated.

CHAPTER II

INJURIES OF JOINTS

SURGICAL ANATOMY--INJURIES: _Contusions_; _Wounds_; _Sprains_;
_Dislocations_--TRAUMATIC DISLOCATIONS: _Causes_: _Varieties_;
_Clinical features_; _Treatment_--Compound
dislocations--Old-standing dislocations.

#Surgical Anatomy.#--The function of a joint is to permit of the
movement of one bone upon another. The articular surfaces are covered
with a thin layer of hyaline cartilage, and are retained in apposition
by the te